5 BA Cap screws

Hello All.

Long shot but does anyone know where I may find some 5 Ba Cap screws?

Thanks

Dont know about 5BA, but could you use M3 instead they will be pretty close and readily available.

Phil

It is a long shot I'm afraid.

Tried Emkay, for example?

Or possibly, ModelFixings (though that company sells mainly metric sizes)?

If you end up having to convert the design to metric, you'd be looking at M3, 3.5 or 4, whichever would be the more appropriate, but for which cap-screws are readily available... e.g. from above?

Alternatively, try UNF cap-screws. These are still fairly easily obtainable (e.g. Westfield Fasteners, possibly those above), and if the engine is in Imperial sizes, at least the UN series is as well.

'

If you have already drilled and tapped the holes you would have to assess whether the replacement is close enough for re-tapping as-is to trim the thread, though that's a horrible practice leading to loose threads; or would need re-drilling and tapping for the nearest size M or UNF above. You might need re-cut the counter-bores as well.

One immediate barrier to the horrible practice is that although actually metric the BA diameters are integer mm in only some sizes, and the thread angle is about 47º whereas M- and UN are of 60º. It might just work for 5BA as that is very close to 3mm dia, (like 0BA / M6, allegedly) but I have not tried it, and would not recommend it for anything critical.

I think you are going to have to consult detailed thread-tables carefully to find a replacement, but the risk is ending up (as I have), with an inelegant mix of thread standards in one machine.

.

Forgive me if I have missed some important detail, Nigel ... but

where did you find reference to “the engine” ?

MichaelG.

Err, Do you know, I am not sure now!

Ah, I think I saw a very similar enquiry maybe on another thread, that does relate to 5BA studs or screws on an engine, so I probably mixed the two up.

Anyway it's not important to the point of the question.

There’s a website www.ba-bolts.co.uk

Have you tried them?

MC Black

If you have tapped for them already then tapping the existing hole out to 4BA would keep the same thread forms and even numbers are available.

If not drilled then go with M3

.

Although, if Brian actually needs screws to fit an existing item, it might possibly restrict the range of viable answers.

MichaelG.

Hello all, thanks for all the reply’s 

Sorry i should have said, the holes are already tapped 5ba, and in steel, but access is tight so i wanted to use cap screws.

I have looked at all the main stream suppliers,

Wonder if 3.5mm would work?

Edited By Brian Abbott on 21/03/2021 10:33:04

I recently acquired some 3 BA screws from a company called GWR Fasteners Ltd. based in Owestry.

They stock and /or will make a large range of BA fasteners.

No connection apart from good service.

www.gwr-fasteners.co.uk

Could you use slotted cheese head screws instead ?

EKP do them
https://www.ekpsupplies.com/5ba-x-3/4-steel-ch/hd-qty-100.html

Phil

Brian

Did you find some screws?

I have a few 10mm long ones, are they long enough, how many do you need?

Rod

How many do you need Brian?

Regards,

IanT

Thanks Rod, really appreciate the offer but i need them to be 3/4 long.

I have found some one size small 5ba hex, not ideal but i think it may just work.

Hello Phil, thanks for the reply it’s cap heads i need,

Thanks all.

Hello Ian.

Ideally 16 but could manage with 8, so so few have have made.

Will see how i get on with the one size smaller.

Thank you.

Brian,

I recently got some 8BA SHC screws from Howard Lee & Son Ltd,. a good old engineers suppliers based in Birmingham. They actually sent me some 9BA initially by mistake so it appears they do have an extensive stock of BA SHC screws. Their lengths started at 1/4" and went up in 1/8th increments to 1". No connections other than a satisfied customer.

My contact was Karen Gracie - email: [email protected]

Martin

Just checked my inside stock Brian. I have 1/2" 4BA cap heads but no 5BA caps I'm afraid.

I do have 5BA 3/4" slotted Cheese heads (in stainless) or 1" Hex head (in steel) if they were suitable though. I may have something else down the Shed but that's not quite so organised at the moment.... I'm just opening up after the winter shut-down...

Regards,

IanT

Have you considered using 4BA socket screws and turning the thread down to the outside diameter of 5BA and then cutting a 5BA thread on them using a die?

Fiddly but it's NOT a large number

MC

babolts.co.uk